| Message ID | E1rVDn9-0027ZB-QN@rmk-PC.armlinux.org.uk |
|---|---|
| State | New |
| Headers | show |
| Series | ACPI/arm64: add support for virtual cpu hotplug | expand |
On Wed, 31 Jan 2024 16:50:27 +0000 Russell King (Oracle) <rmk+kernel@armlinux.org.uk> wrote: > From: James Morse <james.morse@arm.com> > > gic_acpi_match_gicc() is only called via gic_acpi_count_gicr_regions(). > It should only count the number of enabled redistributors, but it > also tries to sanity check the GICC entry, currently returning an > error if the Enabled bit is set, but the gicr_base_address is zero. > > Adding support for the online-capable bit to the sanity check will > complicate it, for no benefit. The existing check implicitly depends on > gic_acpi_count_gicr_regions() previous failing to find any GICR regions > (as it is valid to have gicr_base_address of zero if the redistributors > are described via a GICR entry). > > Instead of complicating the check, remove it. Failures that happen at > this point cause the irqchip not to register, meaning no irqs can be > requested. The kernel grinds to a panic() pretty quickly. > > Without the check, MADT tables that exhibit this problem are still > caught by gic_populate_rdist(), which helpfully also prints what went > wrong: > | CPU4: mpidr 100 has no re-distributor! > > Signed-off-by: James Morse <james.morse@arm.com> > Reviewed-by: Gavin Shan <gshan@redhat.com> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Does what it says on the tin. Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 98b0329b7154..8deb671c4ff7 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -2422,19 +2422,10 @@ static int __init gic_acpi_match_gicc(union acpi_subtable_headers *header, * If GICC is enabled and has valid gicr base address, then it means * GICR base is presented via GICC */ - if (acpi_gicc_is_usable(gicc) && gicc->gicr_base_address) { + if (acpi_gicc_is_usable(gicc) && gicc->gicr_base_address) acpi_data.enabled_rdists++; - return 0; - } - /* - * It's perfectly valid firmware can pass disabled GICC entry, driver - * should not treat as errors, skip the entry instead of probe fail. - */ - if (!acpi_gicc_is_usable(gicc)) - return 0; - - return -ENODEV; + return 0; } static int __init gic_acpi_count_gicr_regions(void)